Adjustable stop mechanism



July 3, 1945,

H. A. STRICKLAND, JR

ADJUSTABLE STOP MECHANISM Filed Sept. 1, 1945 Harold fl) Sirzbliland Jn INVENTOR 6 ATTORNEY chamber of the furnace at a predetermined stop Patented July 3, 1945 r UNITED STATES PATENT OFFICE;

ADJUSTABLE STOP MECHANISM- Harold A. Strickland, J12, Detroit, Mich., assign'or to Budd Wheel Company, Philadelphia, Pa., a y I corporation of Pennsylvania f I I Application September 1, 1943, Serial No. 500,773 7 Claims. V (01. 263- 6).-

This invention relates 'to induction furnaces and more particularly to adjustment mechanism for maintaining'the workpiece within the heating point.

In mycopending application, Serial No. 384.503,

filed March 21, 1941, I have disclosed an electric furnace machine in which utilization is made up of a tubular furnace having open front and rear ends, there being provided a stopat the rear end provements are incorporated. For example in the original arrangement access to the stop holding means. required partial dismantling of the 'furnace whereas in the present application the stop may be adjusted from a point external to the furnace casing. Accordingly, the primary object of the present invention is to provide means whereby the workpiece stop may be adjustably positioned with reference. to the furnace chamber. Still another object of the invention is to provide a stop for a furnace workepiece which may be adjusted from a point external to the furnace casing. An object also is to provide a stop which has universal'adjustability along the axis movement of the stop. Further objects identified with detailed structure of theadjustment mechanism will appear on consideration of the following description and related drawing, in

which: I

Fig. 1 is aview partly in section of a portion of v I the furnace illustrating the relationship of furnace chamber stop and stop adjusting means:

Fig. 2 is a detail showing a side ;view of the adjusting mechanism, and:

v Fig.3 is a front view of the adjusting member.

The furnace generally indicated by the numeral Ill is provided with a casing H, a ventilating screen l2, a base plate l3 and an end plate M, the latter closing the furnace chamber l5 and separating it from the'instrument chamber H5. The furnace generally indicated by the numeral ll has a tubular construction and comprises an induction heating coil l8 having an overlying asbestos bodied coat i9 and inner layers of glass, mica or mica containing material 20. Also within the mica layers are sections of refractory insulation brick 2| supported by rails not shown, to which are attached guide plates 22 for supporting the workpiece. External supporting rails 23 are utilized to maintain the. insulation brick and brick supporting rails within the heat spring 29.

ing chamber." The furnace unit is supported within the casing II by means of C-brackets 24, one of which is shown in Fig. 1,- the same consistingof a base section'25 to which is attached integrally the .C-section. 26 extending partially a'iround and above the furnace. The C-section is provided with adjustable contact screw heads 21 and 28, the latter being of 'U-shape and yieldabl-y associated with the bracket26 through the coil Thestop or .gauge- 30 is of tubular construction and is adapted for axial movementalong the axis of the furnace chamber through the opening 3| ment with the workpiece. to be supported upon the bracket33 boltedto the end plate 14, thisbracket beingofapproxima'tely triangular. shape inv plan as shown in'zFigure 3, with a side projection 34 at one edge having a curved central area 35 for refieption. of the curved stop. tube, .which is adapted to .lie therein as shown in Figure 3. Thesupport section34 of the bracket is of sufiioient width to. cover a substantial section of the stop tube as shown in Figure l. The edge of the .bracket33jrom which,the'sup porting extension 34 extends is also provided with outwardlylextending lugs 36 which are similar and in alignment and provided with pivot receiving. apertures for the reception of the pivot pin '31. The holdingor locking member 38 is mounted on the ,pivot pin 31 between the lugs 36 and is adapted for pivotal movement in a plane perpendicular. to thefurnace casing end plate l4.

' By the term locking? is'meant fixing or holding with reference to the positionof the slidable stop.

As shown inFigures 1 and 2 this locking member .38 is vertically positioned and directly overlies the tubularjstop 30 whichis slidable between the .base of the locking mer nber 38 and the bracket guide 34. I In the construction shown, the lockin member 38 is triangular in shape, having a thickened rear edge 39, the upper end of which is adapted to make contact with the end of an adjusting screw 40, the latter being mountedonthe end plate M in an opening therethrough and havinga lock nut 4| to adjustably secure the screw in any desired set position. The forward edgeof the triangular locking member 38 is relatively thin, but terminates at its lower end 'at the conjunction with the base, of thetriangle in a thickened head 42. This head extends transversely in relation to locking member 38 at 43 and part in the head 42 at the point 44. This notched opening is adapted to receive, by insertion on the side of the locking member the square contact bar 45 which is of metal relatively harder than that of the metal of the locking plate. After insertion the bar is welded or brazed to the metal of the locking member as indicated by the nu-- meral 46, it being observed that when subjected to pressure the bar will not place any strain on the welded joint.

The operation of the mechanism is now apparent. On release of the lock nut 4! and the retracting screw 40, the lock bar 45 may be elevated to a point displaced from the tubular stop 30. Thereupon the tube '30 may readily be shifted axially to move the stop head 32 in relation to the furnace to such a point as may be found desirable for the particular workpiece being heated. At the desired point of adjustment, the screw 40 is moved to compress the bar 45 and which being of relatively harder metal will engage and depress the softer metal of the stop tube. The lock nut 4| is then tightened and the stop tube is held securely in place with adequate resistance to the impact of the workpiece against the stop head 32.

Associated with the stop tube 30 is an ejector or pushout rod 41 which is adapted to lie within the tubular space of the stop'tube extending the full length of the same and in heat treating position extending a substantial distance to the rear thereof. The ejector rod is preferably hollow to permit cooling by the circulation of a coolant through the connecting tubes 48 as shown in Fig. l. Preferably the furnace end of the ejector rod is of refractory material, so as to withstand high temperatures encountered at this point. Secured to the ejector rod is a collar 49 which may be adjustable along the length of the rod and which is adapted to contact with the tip 50 of a bell crank pivoted at 52 on a'bracket 53 fastened to the exterior lower side of the furarm 54 the end of which is apertured to receive to the furnace l9, but that this adjustment is axially universal, there being no fixed series of points to which adjustment must be made as by a stepped stop mechanism. Furthermore it is pointed out that complete adjustment of the stop or gauge may be made at points exterior to the furnace casing. This is of considerable importance in practice since the necessity of removing "the-casing ll for access to the interior of the adjustment and then look the member 38 in its new position, this adjusting operation taking place at a point exterior to the furnace casing. It is further noted also that the means of adjustment described do not interfere in any way "with the action and movement of the ejector rod for normal adjustments. In cases of large adjustments the collar 49 must be moved along rod 41.

Modifications of the invention may be made, the scope of the invention being comprehended in the following claims.

What is claimed is:

1. In heating apparatus, a furnace chamber having an opening through which a workpiece is movable, a slidable stop for limiting the movement of the workpiece through said opening and means for locking said stop at variable points with reference to said chamber, said locking means comprising a'frictional element pivotally mounted adjacent said stop and means imparting pivotal movement to said frictional element to and from said stop whereby the stop may, at will, fixedly hold in any desired position relativeto the furnace chamber.

the end of a coil spring 55, the upper end of which engages the second bracket 56 positioned above the level of the stop tube 30. The outward end of bracket 56 is adapted to support pivotally the cylinder 51 of a fluid pressure unit including a cylinder and piston the piston extending as arod 58 to a pivot 59 secured to the bracket arm 54 intermediate the pivot 52 and spring engaging end thereof. .Fluid under pressure is introduced through the pipe 59 which tends to force the piston downwardly and thereby turning the bell crank so as to force the contact end thereof into engagement with the ejector rod collar 49 and move the ejector. rod inwardly to engage and eject a workpiece from the furnace chamber. This ejecting action of the bell crank 5| is against the tension of the spring so that when the fluid pressure is released in the cylinder 51, the spring pivots the bell crank 51 rearwardly thereby permitting free outward sliding movement of the ejector rod on insertion of anewworkpiece within the heating chamber.

It is of importance to note that not only is the stop tube 30 axially adjustablewith reference 2. In heating apparatus a furnace chamber within said casing having an opening therein through which a workpiece is movable, a stop for limiting movement of the workpiece in relation to said opening and means for locking said stop in any desired position, said locking means being operable at a point external to the furnace casing.

3. In heating apparatus, a furnace casing and a tubular furnace chamber having an opening through which a workpiece is movable, a stop axially aligned with said furnace chamber and in movable relation thereto, an ejector rod positioned adjacent said stop and axiall movable relative thereto and separate means external to said casing for adjusting the axial position of either stop or ejector rod.

4. In heating apparatus a furnace casing and a tubular furnace chamber having an opening through which a workpiece is movable, a tubular stop axially aligned with said furnace chamber and in movable relation thereto, an ejector rod positioned Within said stop and axially movable relative thereto and separate means external to said casing for adjusting the axial position of either stop or ejector rod, including means for locking the stop in any desired position.

5. In adjustment mechanism for heating apparatus, a support plate, a bracket having a curvilinear curve attached to said plate adjacent an aperture formed therein, a stop tube slidable within said plate aperture and in said bracket curve, said tube extending through said aperture to the side opposite of the bracket whereby the same may be adjusted with reference to the plate and frictional holding means for locking said tube in fixed position relative to the plate, said holding means comprising a contact bar, and bar holding means pivotally mounted on said bracket for moving said bar into and out of engagement with said stop tube and means supported by said plate for engaging the pivotal member for forcing the bar into contact with the tube.

HAROLD A. STRICKLAND, JR. 7 

